Assuming my air gauge is accurate, I normally run 20- 35 PSI for
Floquil paint. Polly Scale (water based paints) normally require
slightly more. As for mixing, Floquil suggests 10% thinner, 10% glaze
& 80% paint. With Polly Scale, I normally thin with about 10% water
to start. IF required, I will thin more. Hope this helps. Larry
On 10/8/2007 4:36 PM firstname.lastname@example.org spake thus:
That jibes with my experience for both those paints. Once you start
painting, it'll become obvious pretty quickly whether you have enough
(or too much) pressure.
Better to start with too little pressure and increase it; if you have
too much, you run the risk of both drying the paint too quickly with the
air blast and of pushing the paint around, risking sags and blobs.
With Polly Scale I use a preasure of about 20 lbs PIS and more that not
spray straight from the bottle, Floquil [ for me ] sprays better at 15 lbs
PSI or even 12 lbs. I was spraying Foquil at 20 lbs and the paint was
drying befor it hit the model which results in a " sandpaper " finish.
Like David says start LOW and work up to the preasure that suits you. Ask
your LHS for the Information sheets they [ used to ] put out for the both
paints, I've had mine for years. Also look in the Walthers catalog as
the spray info is some tims there as well
I rarely go over 20 lb for any of my airbrushing. I am usually
between 10-15 lb for most of the paint brands I use. But since I'm
usually painitng very small items (N scale) I don't need wide
coverage. I suppose that if I was painting a side of an O scale
boxcar then I would probably crank up the pressure and paint
Also there is a relation between the viscosity of the paint and
pressure. The thinner the paint is the less pressure you need. And
since one thins their own paint, that affects the air pressure one
uses. There is no fixed formula - everybody has their own methods.
It will vary with the airbrush. When I use my Paasche H3, 25-30 psi is
usually adequate...but when I use my Paasche AU airbrush...which I use 95%
of the time, all that is needed is 10-12 psi.
The "AU" is somewhat of a production airbrush with a pistol grip and can
adjust from 1/8" to over 2" spray area...great for 0 gauge and restoring
tinplate. Have been using both the H3 and "AU" for over 35 years.